A total systems approach to the development of an efficient rapid excavation system should consist of three phases: (1) preliminary systems analysis to identify critical blocks of technology in present excavation systems that will need significant advances before the desired rapid excavation systems can be developed; (2) systems analysis of subsystems research, initiated as a result of preliminary systems analysis, to understand clearly all subsystem or element interfaces, and to obtain research output that is as quantitative as possible and in a format suitable for design of a total rapid excavation system; and (3) final system design, testing, evaluation, and demonstration of “best” rapid excavation systems possible under the set of constraints present.

Even the crudest sensitivity analysis and technological forecasting studies reveal that our present inability to predict accurately critical geological or hydrologic conditions and engineering rock properties of ground ahead of an advancing excavation is one of the greatest deterrents to the successful development of an efficient rapid underground excavation system. Earth scientists must develop new and accurate means of detecting and quantitatively describing critical geological and hydrologic conditions during the pre-excavation, excavation, and immediate postexcavation phases of these operations. Geologists should also learn to characterize environments subject to excavation with probability functions for the occurrence of each type of geological hazard to be expected in the area so that maximum use can be made of mathematical models used in a stochastic mode.